This invention relates to reclosable paperboard cartons. More particularly it is directed at a lightweight but strong paperboard carton characterized by a paperboard sift-proof reclosable pour spout that is configured to permit easy opening, scatter-free pouring, and ready reclosing and reopening.
Cartons made of paperboard having a pour spout in a side partition or on the top or bottom are well-known in the art. Such cartons are particularly well suited to serve as packages for sugar, starch, dry milk, cereal and other granular or powdered items particularly those which are subject to intermittent use by the ultimate consumer. The paperboard pour spout provides a convenient and economical means by which a portion of the contents of the carton may be removed for use. Yet, the spout permits the carton to be reclosed to preserve the remaining material and to protect it against spillage in case of accidental dropping or turning over.
There are a number of desirable attributes that a pour spout paperboard carton should have to maximize its utility and economy. The carton and blank from which it is formed should be readily constructed and particularly amenable to automatic manufacture. Moreover, the resultant carton desirably is strong and resilient enough to absorb the rigors of the marketplace without breaking. Yet, this ready construction and operative strength must be effected with minimal material waste.
The pour spout itself should likewise be of simple construction and afford ready opening and reclosing by the consumer. It should be formed to provide sift-proof packaging of small grained powders and to withstand repeated openings and closings. Further, the spout and related tabs should facilitate content pouring and not serve to scatter the poured powder.
A number of prior art reclosable paperboard cartons accomplish some of these desired objectives. For example, U.S. Pat. Nos. 3,708,109 and 2,361,597 disclose machine-manufactured flip-top type paperboard cartons but neither are sift-proof, being more specifically constructed to package cigars or cigarettes. Moreover, these cartons do not admit easy opening as their opening tabs are available only after glue seal fracture by external pressure. U.S. Pat. No. 3,361,327 discloses an entire top opening container. Again, the initial carton opening must be preceded by external pressure to break the seal of a tearaway top. In remedy of this disadvantageous opening sequence, U.S. Pat. Nos. 3,861,583 and 2,162,556 disclose entire top opening cartons which are characterized by an unattached tab for ready opening. Moreover, U.S. Pat. No. 3,861,583 is assembled from a dual blank of specific shape to minimize paperboard waste. However, none of these cartons are designed for removal of the contents by pouring.
U.S. Pat. Nos. 1,947,865, 2,351,812 and 3,397,833 disclose paperboard cartons which include reclosable pour spouts. However, none admit easy opening. U.S. Pat. No. 2,351,812 requires thin instrument insertion to open (FIG. 2) and U.S. Pat. Nos. 1,947,865 and 3,397,833 require external pressure to break the glue seals and perforations. Moreover, none are sift-proof, each having perforations in communication with the packaged contents. And, at least the carton tab of U.S. Pat. No. 1,947,865 operates to scatter the contents during pouring as the tab extends in the same direction as the pour.
U.S. Pat. Nos. 1,470,705 and 2,931,554 provide unattached tab tongues to avail easy opening of the paperboard pour spout. Further, U.S. Pat. No. 1,470,705 includes a notched end flap portion (32) to aid reopening (FIG. 5). However, neither of these cartons provide sift-proof seals, again the perforation are in communication with the contents. Additionally, the carton of U.S. Pat. No. 1,470,705 is not easily closed as the tab tongue is often blocked by end flap (17) of the carton top during attempted insertion of this tongue between the end flap and dust flaps (15 and 16) (FIGS. 3 and 5).
U.S. Pat. Nos. 3,372,853 and 3,438,565 likewise disclose paperboard cartons with reclosable pour spouts. Both, provide unattached tongues or tabs to permit easy carton opening. However, that of U.S. Pat. No. 3,372,853 is neither sift-proof nor amenable to content pouring without tab interference and scattering. Conversely, the spout of U.S. Pat. No. 3,438,565 is sift-proof, lid portion (74) being larger than and overlying removable spout section (44) and its perforated boundaries (FIG. 3). However, the blank from which the carton of U.S. Pat. No. 3,438,565 is constructed is not easily fabricated. Instead, triangular section 50 must be cut scored into the blank to about one-half the depth of the blank so as to allow section 68 to be peeled therefrom. Moreover, full cut slits 56 and 58 must also be provided in this blank section. The carton of U.S. Pat. No. 3,438,565 is also not easily reopened after closing. Instead tongue 90 has been pushed within the top of the box and is only retrieved with inconvenience.